ive only been once and ive only done 3 laps in rather bog standard s14,
If you drive way within your and the cars limits your fine, I think the rumors about thousands of pounds on shut down costs are a bit OTT within my group of friends we've had 2 drivers damage armco and the paid no more than £600 for replacement parts and labour, but then they didnt shut the track they just put like coned everyone into single file for a few hundred yards at them spots, and at the end of the day you can just drive around it at 30mph if you wish.